Lock nut



May 30, 1950 J. F. LIPSCOMB LOCK NUT Filed Aug. 27, 1945 %aj m Patented May 30, 1950 UNITED STATES PATEN T OFFICE LOCK NUT John F. Lipscomb, Elkhart, Ind., assignor, by

nesne assi'gnments, to Security 'Locknut Cor- Donation, Ghicago, Ill., a corporationtof lllinois Application August ,27, 1945, Serial No. 61%,810

1 claim. i

This invention relates to lock nuts andtmorze particularly to a nut construction which will remain tight on a bolt or the like under substantially all conditions of use.

It is one of the objects of the invention to provide a lock nut which ofiers a minimum resistance to threading on to a bolt and a maximum resistance to removal from the bolt.

Another object is to provide a lock nut which is substantially insensitive to vibration and which will remain tight over long periods of use.

Still another object is to provide a lock nut which is simple and inexpensive to manufacture and assemble.

The above and other objects and advantages of the invention will be more readily apparent from the following description when read in connection with the accompanying drawing, in which- Figure 1 is a top plan View of a lock nut embodying the invention;

Figures 2, 3 and 4 are sections respectively on the lines 2-2, 3-3 and 4-4 of Figure 1; and

Figure 5 is a plan View of the looking ring.

The nut as illustrated in the drawing is generally similar to that disclosed in the patent to Green, No. 1,986,891, and comprises a nut body II) which may be hexagonally shaped on its exterior and which is formed on its interior with a threaded cylindrical bore I l. At its upper end the nut body is forned with a cylindrical recess !2 coaxial with the bore H and formed with smooth interier walls interrupted at one side by a peripheral notch [3 extending throughout the axial length of the recess.

The recess is adapted to receive a looking ring !4 which is interiorly threaded with threads forming a continuation of the threads in the bore II so that when a nut is threaded through the bore I! it will continue to thread into the ring M. The ring is initially formed generally oval shaped with its major axis as indicated at 15 in Fgure 5, and its minor aXis at !6. When Originally ormed, the major axis [5 of the ring is slightly in excess of the diameter of the recess l2. When the ring is to be assembled in the recess, its major axis is squeezed in slightly so that when it is in place in the recess it will tend to expand against the sides of the recess to hold the ring in place therein. It will be noted, as Originally formed and even when assembled, the interior diameter of the ring along its minor axis is slightly shorter than the diameter of a bolt on which the ring is to be threaded so that the ring will frictionally grip the bolt to resist rotation thereon.

The ring is held against rotation relative to the nut body by a projecting lug IT formed at one side of the ring to fit into the notch !3. The lug is located between the ends of the major and minor axes of the ring and is displaced from the minor axis in the same direction in which the ring is turned to unscrew it from the bolt as indicated by the arrow |8 in Figure 5.

In using the lock nut of the invention, the nut body is placed on a threaded bolt 01' rod and is turned in the usual manner to draw it on to the threads on the bolt or rod. As the end of the bolt or rod reaches the upper end of the threaded bore ll, it starts to thread into the ring !4 causing the ring to expand slightly alon its minor axis so that the ring will frictionally grip the bolt. Engagement of the lug with the notch !3 prevents turning of the ring in the recess |2 at this time. Preferably the threads in the ring are slightly out of alignment with those in the nut body so that the ring will rise slightly from the nut body. This reduces the efiect of nut body vibration on the ring and wear on the ring threads.

By reference to Fgure 5 it will be noted that the turning force exerted on the ring 14 is applied through the lug I 'I in a clockwise direction so that the ring tends to be drawn in along its major axis to become more nearly round. This turning force on the ring facilitates threading it on to the bolt so that it can be screwed on without requiring exertion of a large force. When the nut is threaded on to the bolt, any tendency of the nut to unscrew exerts a force on the lug I 1 in the direction of the arrow !8 of Figure 5. This force tends to draw the ring in along its minor axis causing the ring to wrap down tightly against the bolt so that unscrewing of the nut will be resisted by a force substantially larger than that required to thread the nut on to the bolt. I have found that with a Construction as shown this force will be several times that required to thread the nut on to the bolt. Furthermore, since the ring is physically separated from the nut body, any vibrations acting on the relatively larger mass of the nut body act only to a much smaller degree on the ring and are insuflicient to cause loosening or unthreading of the ring. Therefore, the only forces tending to unscrew the ring are those acting on it through the lug IT to produce the wrap down eifect, causing the ring to grip the bolt tightly and to prevent it from unscrewing.

With a single ear construction the ring can easily be assembled in the recess in proper position to provide the proper relationship between the threads. Also the ring can centralize itself accurately in the recess when the nut is threaded on a bolt to eliminate binding and uneven strain on the ring.

While only one embodiment of the invention has been shown and described in detail herein,

it is to be understood that it is illustrative only m and is not to be taken as a definition of the scope of the invention, reference being had for this purpose to the appended claim.

What I claim is:

A lock nut comprisng a threaded nut body 15 formed at one end with a, substantially cylindrical recess coaxial with the threads, the recess having a single notch in one side only thereof, a threaded looking ring fitting in the recess, the looking ring being generally oval and having its minor axis less than the diameter of a bolt on which it is to be threaded whereby it will fric- REFERENCES CITED The following references are of record in the V file of this patent:

UNITED STATES PATENTS Number Name Date 20 1,623,686 Kolthofi Apr. 5, 1927 1,986,891 Green Jan. 8, 1935 2,399,639 Kelly May '7, 1946 

